CVE-2024-11481

Executive Summary

CVE-2024-11481 is a critical vulnerability in McAfee Enterprise Security Manager (ESM) version 11.6.10. The flaw allows an unauthenticated attacker to access internal API endpoints, specifically the Snowservice API, due to improper path traversal validation and insecure forwarding to an AJP backend. This can lead to full system compromise, data exfiltration, and lateral movement within the network. The vulnerability has a CVSS score of 8.2, indicating high severity, and no patch is currently available.

CVSS Breakdown & Threat Level

• CVSS Score: 8.2 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: High (A:H)

The threat level is critical due to the lack of authentication required and the potential for complete system compromise.

Deep Dive & Mechanics

The vulnerability resides in the Snowservice API within McAfee ESM 11.6.10. The API is intended for internal use but is exposed without proper authentication. The core issues are:

1. Path Traversal: The API does not properly sanitize user-supplied paths, allowing an attacker to traverse directories and access files outside the intended scope.
2. Insecure AJP Forwarding: The system forwards requests to an AJP (Apache JServ Protocol) backend without adequate validation. This can be exploited to send malicious requests to internal services.
3. Lack of Authentication: The internal API endpoints are accessible without any authentication, enabling unauthenticated attackers to interact with sensitive backend services.

An attacker can craft HTTP requests to the Snowservice API, using path traversal sequences (e.g., ../) to access arbitrary files or trigger actions on the AJP backend. This can lead to remote code execution, data theft, or further exploitation of internal systems.

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, the vulnerable code likely lacks input validation and authentication checks. A patched version would need to:

• Implement strict input validation to prevent path traversal.
• Require authentication for all API endpoints.
• Validate and sanitize all forwarded requests to the AJP backend.

Exploitation & Lab Setup

Red Team

To simulate exploitation, set up a lab with McAfee ESM 11.6.10. Use the following steps:

1. Identify the Snowservice API endpoint: Typically found at /snowservice/ or similar.
2. Craft a path traversal request:

   curl -v "http://target-ip:port/snowservice/../../../etc/passwd"
   

3. Exploit AJP forwarding: Use tools like ajpy or custom scripts to send malicious AJP packets.

   import socket
   # Example AJP forward request
   s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
   s.connect(("target-ip", 8009))
   # Craft AJP packet with path traversal
   packet = b"\x12\x34"  # Placeholder
   s.send(packet)
   response = s.recv(4096)
   print(response)
   

Blue Team

To detect exploitation attempts:

• Monitor for unusual HTTP requests containing ../ or %2e%2e/ patterns.
• Alert on connections to the Snowservice API from untrusted IPs.
• Use network segmentation to limit access to the AJP port (8009).

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /snowservice/ with path traversal sequences.
  • Connections to port 8009 (AJP) from unexpected sources.
• File IOCs:
  • Unauthorized access to /etc/passwd, /etc/shadow, or other sensitive files.
• Log IOCs:
  • ESM logs showing failed authentication attempts or unusual API calls.

Detection Engineering

YARA Rule

rule CVE_2024_11481_Snowservice_Path_Traversal {
    meta:
        description = "Detects path traversal attempts targeting McAfee ESM Snowservice API"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-11481"
    strings:
        $path_traversal = /\.\.\/|%2e%2e%2f|%2e%2e\//
        $snowservice = "/snowservice/"
    condition:
        $snowservice and $path_traversal
}

Sigma Rule

title: CVE-2024-11481 McAfee ESM Snowservice Path Traversal
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects path traversal attempts against McAfee ESM Snowservice API
author: Valters IT
date: 2024-01-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - "/snowservice/"
            - "../"
            - "%2e%2e/"
    condition: selection
falsepositives:
    - Legitimate use of path traversal in other contexts
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-11481 McAfee ESM Snowservice Path Traversal"; flow:to_server; content:"/snowservice/"; http_uri; content:"../"; distance:0; within:100; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Since no patch is available, immediate mitigation steps include:

1. Network Segmentation: Restrict access to the Snowservice API and AJP port (8009) to trusted internal networks only.
2. Web Application Firewall (WAF): Deploy WAF rules to block path traversal patterns and unauthorized API access.
3. Authentication: Implement additional authentication layers, such as VPN or IP whitelisting, for accessing the ESM interface.
4. Monitor Logs: Continuously monitor logs for suspicious activity and set up alerts for path traversal attempts.
5. Vendor Contact: Contact McAfee for a patch or workaround. Consider upgrading to a newer version if available.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert